CVE-2018-0296: Cisco Adaptive Security Appliance (ASA) Denial-of-Service Vulnerability

Vulnerability summary

CVE-2018-0296 is a high (CVSS 7.5) Improper Input Validation vulnerability in Cisco Adaptive Security Appliance (ASA). It is known to be exploited: CISA lists it, first on 03-11-2021. EPSS estimates a 99.91% chance of exploitation in the next 30 days, higher than 99.9% of scored vulnerabilities. 4 public exploits are recorded.

Timeline

1. 07-06-2018
   PublishedVulnerability first disclosed.
2. 03-11-2021
   Added to CISA KEVCisco Adaptive Security Appliance (ASA) Denial-of-Service Vulnerability
3. 03-05-2022
   CISA remediation dueApply updates per vendor instructions.
4. 12-01-2026
   Last modifiedVulnerability information updated.

Description

A vulnerability in the web interface of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. It is also possible on certain software releases that the ASA will not reload, but an attacker could view sensitive system information without authentication by using directory traversal techniques. The vulnerability is due to lack of proper input validation of the HTTP URL. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. An exploit could allow the attacker to cause a DoS condition or unauthenticated disclosure of information. This vulnerability applies to IPv4 and IPv6 HTTP traffic. This vulnerability affects Cisco ASA Software and Cisco Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 1000V Cloud Firewall, ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4100 Series Security Appliance, Firepower 9300 ASA Security Module, FTD Virtual (FTDv). Cisco Bug IDs: CSCvi16029.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.